/*
* Copyright (C) 2006 Ondrej Palkovsky
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _BITOPS_H_
#define _BITOPS_H_
#include <typedefs.h>
/** Return position of first non-zero bit from left (i.e. [log_2(arg)]).
*
* If number is zero, it returns 0
*/
static inline int fnzb32(__u32 arg)
{
int n = 0;
if (arg >> 16) { arg >>= 16;n += 16;}
if (arg >> 8) { arg >>= 8; n += 8;}
if (arg >> 4) { arg >>= 4; n += 4;}
if (arg >> 2) { arg >>= 2; n+=2;}
if (arg >> 1) { arg >>= 1; n+=1;}
return n;
}
static inline int fnzb64(__u64 arg)
{
int n = 0;
if (arg >> 32) { arg >>= 32;n += 32;}
return n + fnzb32((__u32) arg);
}
#define fnzb(x) fnzb32(x)
#endif